1. Field of the Invention
The invention relates to a serial fan, and in particular to a serial fan providing at least one connecting element formed with a plurality of air-guiding recesses.
2. Description of the Related Art
FIG. 1 is an exploded view of two serial fans R assembled in series. The assembled fans R comprise a first fan 1 and a second fan 3 which have the same structure. The first fan 1 comprises a housing 10 and an impeller 11 disposed in the housing 10, and the second fan 3 comprises a housing 30 and an impeller 31 disposed in the housing 30. The housing 10 of the first fan 1 comprises a frame 101, a seat 102 disposed in the frame 101, and a plurality of ribs 103 disposed between the frame 101 and the seat 102. The housing 30 of the second fan 3 comprises a frame 301, a seat 302 disposed in the frame 301, and a plurality of ribs 303 disposed between the frame 301 to the seat 302. The configuration of the assembled fans R can increase airflow efficiency.
When the air sequentially travels through the impeller 11 and the ribs 103 of the first fan 1 and the ribs 303 and the impeller 31 of the second fan 3, however, the wind shear and noise are relatively increased.